1. Field of the Invention
The present invention relates to a vehicle routing and guidance system and, more particularly, to a vehicle routing and guidance comprising a navigation system that includes a self-locating means for the vehicle and a central server for making of navigational information available to the navigation system, whereby the navigational system communicates with the central server at least temporarily by means of transmitter and receiver devices.
2. Prior Art
Vehicle-based navigation systems are known for guidance of vehicles. These systems use map information required for navigation in the vehicle in order to guide the vehicle to a destination point predetermined by the operator of the vehicle. All information required for the entire route is supplied in the vehicle. It is disadvantageous however that a correspondingly large memory capacity is required for the memory used in the navigation system for a number of different destinations over a comparatively large region or territory. Furthermore it is also disadvantageous that information effecting the destination of the vehicle, for example detours, road blockages and so on, is not considered.
Furthermore central server for preparation of navigational data are known, by means of which routes corresponding to a destination predetermined by the operator of the vehicle are transmitted to the vehicle-based navigation system. The entire navigational information for the chosen destination is transmitted. It is disadvantageous therefore that a comparatively large amount of information is to be transmitted and changes during travel over the route can no longer be considered.
By "route" a section of a digital chart or map with at least one destination, which is useable in a vehicle-based navigation system, is to be understood. For guidance to the destination the vehicle must be located on the digital chart, which means the route.
Furthermore vehicle routing and guidance systems are known that include traffic guidance devices arranged at fixed locations along a path of travel of the vehicle, by means of which navigational information corresponding to the selected route is transmitted from those traffic guidance devices that the vehicle passes during its travel.